Changes in the TMJ disc-condyle-fossa relationship following functional treatment of skeletal Class II Division 1 malocclusion: a magnetic resonance imaging study.

A detailed clinical examination of the parts of the temporomandibular joint can be carried out by means of magnetic resonance imaging. The aim of this study was to examine, with the use of magnetic resonance imaging, the mandibular condyle-disc-fossa relationship in subjects with Class II Division 1 malocclusions who were treated with the Andresen activator. The sample consisted of 18 subjects with Class II Division 1 malocclusion, 9 treated with the Andresen activator and 9 control subjects. Unilateral magnetic resonance images, lateral cephalograms, and hand-wrist films were taken for each subject at the beginning and end of the treatment or observation period. The anterior, posterior, and superior joint spaces were measured on the magnetic resonance images, and the posterior, medial, and anterior disc angles were measured for the determination of the disc position. The changes that occurred during the treatment and observation periods were examined by means of a paired t test and an analysis of variance. The condyle was found to be located anteriorly. However, the changes in the disc position were found to be statistically insignificant.